Upregulation of P2X7 Exacerbates Myocardial Ischemia-Reperfusion Injury through Enhancing Inflammation and Apoptosis in Diabetic Mice.

Diabetes-aggravated myocardial ischemia-reperfusion (MI/R) injury remains an urgent medical issue, and the molecular mechanisms involved with diabetes and MI/R injury remain largely unknown. Previous studies have shown that inflammation and P2X7 signaling participate in the pathogenesis of the heart under individual conditions. It remains to be explored if P2X7 signaling is exacerbated or alleviated under double insults. We established a high-fat diet and streptozotocin-induced diabetic mouse model, and we compared the differences in immune cell infiltration and P2X7 expression between diabetic and nondiabetic mice after 24 h of reperfusion. The antagonist and agonist of P2X7 were administered before and after MI/R. Our study showed that the MI/R injury of diabetic mice was characterized by increased infarct area, impaired ventricular contractility, more apoptosis, aggravated immune cell infiltration, and overactive P2X7 signaling compared with nondiabetic mice. The major trigger of increased P2X7 was the MI/R-induced recruitment of monocytes and macrophages, and diabetes can be a synergistic factor in this process. Administration of P2X7 agonist eliminated the differences in MI/R injury between nondiabetic mice and diabetic mice. Both 2 wk of brilliant blue G injection before MI/R and acutely administered A438079 at the time of MI/R injury attenuated the role of diabetes in exacerbating MI/R injury, as evidenced by decreased infarct size, improved cardiac function, and inhibition of apoptosis. Additionally, brilliant blue G blockade decreased the heart rate after MI/R, which was accompanied by downregulation of tyrosine hydroxylase expression and nerve growth factor transcription. In conclusion, targeting P2X7 may be a promising strategy for reducing the risk of MI/R injury in diabetes.

Chaotropic Effect-Induced Sol-Gel Transition and Radical Stabilization for Bacterially Sensitive Near-Infrared Photothermal Therapy.

Deep-seated bacterial infections (DBIs) are stubborn and deeply penetrate tissues. Eliminating deep-seated bacteria and promoting tissue regeneration remain great challenges. Here, a novel radical-containing hydrogel (SFT-B Gel) cross-linked by a chaotropic effect was designed for the sensing of DBIs and near-infrared photothermal therapy (NIR-II PTT). A silk fibroin solution stained with 4,4',4″-(1,3,5-triazine-2,4,6-triyl)tris(1-methylpyridin-1-ium) (TPT3+) was employed as the backbone, which could be cross-linked by a closo-dodecaborate cluster (B12H122-) through a chaotropic effect to form the SFT-B Gel. More interestingly, the SFT-B Gel exhibited the ability to sense DBIs, which could generate a TPT2+• radical with obvious color changes in the presence of bacteria. The radical-containing SFT-B Gel (SFT-B★ Gel) possessed strong NIR-II absorption and a remarkable photothermal effect, thus demonstrating excellent NIR-II PTT antibacterial activity for the treatment of DBIs. This work provides a new approach for the construction of intelligent hydrogels with unique properties using a chaotropic effect.

High-precision Helicobacter pylori infection diagnosis using a dual-element multimodal gas sensor array.

Helicobacter pylori (H. pylori) is a globally widespread bacterial infection. Early diagnosis of this infection is vital for public and individual health. Prevalent diagnosis methods like the isotope 13C or 14C labelled urea breath test (UBT) are not convenient and may do harm to the human body. The use of cross-response gas sensor arrays (GSAs) is an alternative way for label-free detection of metabolite changes in exhaled breath (EB). However, conventional GSAs are complex to prepare, lack reliability, and fail to discriminate subtle changes in EB due to the use of numerous sensing elements and single dimensional signal. This work presents a dual-element multimodal GSA empowered with multimodal sensing signals including conductance (G), capacitance (C), and dissipation factor (DF) to improve the ability for gas recognition and H. pylori-infection diagnosis. Sensitized by poly(diallyldimethylammonium chloride) (PDDA) and the metal-organic framework material NH2-UiO66, the dual-element graphene oxide (GO)-composite GSAs exhibited a high specific surface area and abundant adsorption sites, resulting in high sensitivity, repeatability, and fast response/recovery speed in all three signals. The multimodal sensing signals with rich sensing features allowed the GSA to detect various physicochemical properties of gas analytes, such as charge transfer and polarization ability, enhancing the sensing capabilities for gas discrimination. The dual-element GSA could differentiate different typical standard gases and non-dehumidified EB samples, demonstrating the advantages in EB analysis. In a case-control clinical study on 52 clinical EB samples, the diagnosis model based on the multimodal GSA achieved an accuracy of 94.1%, a sensitivity of 100%, and a specificity of 90.9% for diagnosing H. pylori infection, offering a promising strategy for developing an accurate, non-invasive and label-free method for disease diagnosis.

Effects of Zinc Oxide Nanoparticles on Growth, Development, and Flavonoid Synthesis in Ginkgo biloba.

Ginkgo biloba is a highly valuable medicinal plant known for its rich secondary metabolites, including flavonoids. Zinc oxide nanoparticles (ZnO-NPs) can be used as nanofertilizers and nano-growth regulators to promote plant growth and development. However, little is known about the effects of ZnO-NPs on flavonoids in G. biloba. In this study, G. biloba was treated with different concentrations of ZnO-NPs (25, 50, 100 mg/L), and it was found that 25 mg/L of ZnO-NPs enhanced G. biloba fresh weight, dry weight, zinc content, and flavonoids, while 50 and 100 mg/L had an inhibitory effect on plant growth. Furthermore, quantitative reverse transcription (qRT)-PCR revealed that the increased total flavonoids and flavonols were mainly due to the promotion of the expression of flavonol structural genes such as GbF3H, GbF3'H, and GbFLS. Additionally, when the GbF3H gene was overexpressed in tobacco and G. biloba calli, an increase in total flavonoid content was observed. These findings indicate that 25 mg/L of ZnO-NPs play a crucial role in G. biloba growth and the accumulation of flavonoids, which can potentially promote the yield and quality of G. biloba in production.

KLF9 regulates PRDX6 expression in hyperglycemia-aggravated bupivacaine neurotoxicity.

BACKGROUND: Neurotoxicity induced by local anesthetics (LAs) is potentially life threatening, especially for patients with underlying diseases like diabetes. The anesthetic bupivacaine (Bup) has been reported to induce neurotoxicity mediated by reactive oxygen species (ROS), which is aggravated by hyperglycemia. Krüppel-like factor 9 (KLF9), an axon growth-suppressing transcription factor, plays a key role in neuronal maturation and promotes oxidative stress. This study was designed to investigate whether and how KLF9 regulates ROS levels related to LA neurotoxicity under hyperglycemic conditions. METHODS: Klf9/GFP ShRNA (LV Sh-Klf9) was used to achieve stable Klf9 knockdown in the SH-SY5Y cell line. KLF9-deficient and normal cells were cultured under normal or high-glucose (HG) culture conditions and then exposed to Bup. Cell viability, intracellular and mitochondrial ROS, and mitochondrial membrane potential (ΔΨm) were detected to examine the role of KLF9. Thereafter, KLF9-deficient and normal cells were pretreated with small-interfering RNA targeting peroxiredoxin 6 (siRNA-Prdx6) to determine if PRDX6 was the target protein in HG-aggravated Bup neurotoxicity. RESULTS: The mRNA and protein levels of KLF9 were increased after Bup and hyperglycemia treatment. In addition, cell survival and mitochondrial function were significantly improved, and ROS production was decreased after Sh-Klf9 treatment compared with Sh-Ctrl. Furthermore, the expression of PRDX6 was suppressed by Bup in hyperglycemic cultures and was upregulated in the Sh-Klf9 group. Moreover, the protection provided by KLF9 deficiency for cell survival, the increase in ROS production in cells and mitochondria, and the disruption of mitochondrial function were abolished by Prdx6 knockdown. CONCLUSIONS: The results of this study demonstrated that hyperglycemia aggravated Bup neurotoxicity by upregulating KLF9 expression, which repressed the antioxidant PRDX6 and led to mitochondrial dysfunction, ROS burst, and cell death. Understanding this mechanism may, thus, offer valuable insights for the prevention and treatment of neurotoxicity induced by LAs, especially in diabetic patients.

Exaggerated activities of TRPM7 underlie bupivacaine-induced neurotoxicity in the SH-SY5Y cells preconditioned with high glucose.

Hyperglycemia is considered a risk factor for the enhancement of local anesthetic-induced neurotoxicity. Transient receptor potential melastatin 7 (TRPM7), a kinase-coupled cation channel, has been implicated in a variety of neuropathological processes, including intracellular calcium disturbance and high glucose-induced neuropathy. In this study, we investigated whether TRPM7-related pathophysiology is involved in bupivacaine-induced neurotoxicity in SH-SY5Y cells and how hyperglycemia acts as a risk factor. For initial neurotoxicity evaluation, it was confirmed that cell damage and apoptosis induced by acute exposure to bupivacaine were dependent on its concentration and glucose preconditioning. High glucose preconditioning facilitated the bupivacaine-induced fast and temporary rise in intracellular free calcium concentration ([Ca2+ ]i ), which was attributed to both calcium influx through TRPM7 and calcium store release. Additionally, bupivacaine was shown to increase TRPM7-like currents, particularly in cells preconditioned with high glucose. Bupivacaine-induced neurotoxicity in hyperglycemia was correlated with extracellular signal-regulated kinase (ERK), but not protein kinase B (AKT) activation. Inhibition of TRPM7 and ERK activity alleviates bupivacaine neurotoxicity. These results suggest that therapeutically targeting TRPM7-related pathophysiological changes could be a potential strategy for treating local anesthetic-induced neurotoxicity exacerbated by hyperglycemia.

Prenatal Exposure to Ketamine Leads to Anxiety-Like Behaviors and Dysfunction in Bed Nucleus of Stria Terminalis.

BACKGROUND: Both the clinical and preclinical studies have suggested embryonic or infant exposure to ketamine, a general anesthetic, pose a great threat to the developing brain. However, it remains unclear how ketamine may contribute to the brain dysfunctions. METHODS: A mouse model of prenatal exposure to ketamine was generated by i.m. injection and continuous i.p. infusion of pregnant mice. Open field test and elevated plus maze test were used to analyze the behavioral alterations induced by ketamine. Immunostaining by c-Fos was used to map the neuron activity. Chemogenetic modulation of the neurons was used to rescue the abnormal neuron activity and behaviors. RESULTS: Here we show that mice prenatally exposed to ketamine displayed anxiety-like behaviors during adulthood, but not during puberty. C-Fos immunostaining identified abnormal neuronal activity in Bed Nucleus of the Stria Terminalis, the silencing of which by chemogenetics restores the anxiety-like behaviors. CONCLUSIONS: Taken together, these results demonstrate a circuitry mechanism of ketamine-induced anxiety-like behaviors.

Response of Chinese Anesthesiologists to the COVID-19 Outbreak.

The coronavirus disease 2019, named COVID-19 officially by the World Health Organization (Geneva, Switzerland) on February 12, 2020, has spread at unprecedented speed. After the first outbreak in Wuhan, China, Chinese anesthesiologists encountered increasing numbers of infected patients since December 2019. Because the main route of transmission is via respiratory droplets and close contact, anesthesia providers are at a high risk when responding to the devastating mass emergency. So far, actions have been taken including but not limited to nationwide actions and online education regarding special procedures of airway management, oxygen therapy, ventilation support, hemodynamic management, sedation, and analgesia. As the epidemic situation has lasted for months (thus far), special platforms have also been set up to provide free mental health care to all anesthesia providers participating in acute and critical caring for COVID-19 patients. The current article documents the actions taken, lesson learned, and future work needed.

Ferrostatin-1 alleviates lipopolysaccharide-induced acute lung injury via inhibiting ferroptosis.

BACKGROUND: Ferroptosis is a newly recognized type of cell death, which is different from traditional necrosis, apoptosis or autophagic cell death. However, the position of ferroptosis in lipopolysaccharide (LPS)-induced acute lung injury (ALI) has not been explored intensively so far. In this study, we mainly analyzed the relationship between ferroptosis and LPS-induced ALI. METHODS: In this study, a human bronchial epithelial cell line, BEAS-2B, was treated with LPS and ferrostatin-1 (Fer-1, ferroptosis inhibitor). The cell viability was measured using CCK-8. Additionally, the levels of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and iron, as well as the protein level of SLC7A11 and GPX4, were measured in different groups. To further confirm the in vitro results, an ALI model was induced by LPS in mice, and the therapeutic action of Fer-1 and ferroptosis level in lung tissues were evaluated. RESULTS: The cell viability of BEAS-2B was down-regulated by LPS treatment, together with the ferroptosis markers SLC7A11 and GPX4, while the levels of MDA, 4-HNE and total iron were increased by LPS treatment in a dose-dependent manner, which could be rescued by Fer-1. The results of the in vivo experiment also indicated that Fer-1 exerted therapeutic action against LPS-induced ALI, and down-regulated the ferroptosis level in lung tissues. CONCLUSIONS: Our study indicated that ferroptosis has an important role in the progression of LPS-induced ALI, and ferroptosis may become a novel target in the treatment of ALI patients.

ß2AR-HIF-1α-CXCL12 signaling of osteoblasts activated by isoproterenol promotes migration and invasion of prostate cancer cells.

BACKGROUND: Chronic stress is well known to promote tumor progression, however, little is known whether chronic stress-mediated regulation of osteoblasts contributes to the migration and invasion of metastatic cancer cells. METHODS: The proliferation, migration and invasion of prostate cancer cells were assessed by CCK-8 and transwell assay. HIF-1α expression of osteoblasts and epithelial-mesenchymal transition (EMT) markers of prostate cancer cells were examined by Western blot. The mRNA level of cytokines associated with bone metastasis in osteoblasts and EMT markers in PC-3 and DU145 cells were performed by qRT-PCR. Functional rescue experiment of cells were performed by using siRNA, plasmid transfection and inhibitor treatment. RESULTS: Isoproterenol (ISO), a pharmacological surrogate of sympathetic nerve activation induced by chronic stress, exhibited no direct effect on migration and invasion of PC-3 and DU145 prostate cancer cells. Whereas, osteoblasts pretreated with ISO promoted EMT, migration and invasion of PC-3 and DU145 cells, which could be inhibited by ß2AR inhibitor. Mechanistically, ISO increased the secretion of CXCL12 via the ß2AR-HIF-1α signaling in osteoblasts. Moreover, overexpression of HIF-1α osteoblasts promoted migration and invasion of PC-3 and DU145 cells, which was inhibited by addition of recombinant knockdown of CXCR4 in PC-3 and DU145 cells, and inhibiting CXCL12-CXCR4 signaling with LY2510924 blunted the effects of osteoblasts in response to ISO on EMT and migration as well as invasion of PC-3 and DU145 cells. CONCLUSIONS: These findings demonstrated that ß2AR-HIF-1α-CXCL12 signaling in osteoblasts facilitates migration and invasion as well as EMT of prostate cancer cells, and may play a potential role in affecting bone metastasis of prostate cancer.

Role of mitochondrial Ca2+ uniporter in remifentanil-induced postoperative allodynia.

Opioid-induced hyperalgesia (OIH) and allodynia is a well-known phenomenon and refers to the pain sensitization in patients after prolonged opioid exposure. OIH limits the use of opioids in pain control, but the underlying mechanisms are not fully clear. This study investigated the role of mitochondrial Ca2+ uniporter (MCU) in remifentanil (a commonly used opioid analgesic)-induced allodynia. Using a rat model of OIH, we found that incision- and remifentanil-induced mechanical allodynia were remarkably attenuated by pretreatment with Ru360, a specific MCU antagonist, suggesting a critical role of MCU in both incision- and opioid-induced allodynia. In addition, imaging studies with Rhod-2 (a mitochondrial Ca2+ dye) in spinal tissues demonstrated increased mitochondrial Ca2+ level in response to incision and remifentanil infusion, which was attenuated by Ru360. Western blot and immunohistochemistry showed that pNR [phosphorylated N-methyl-D-aspartate (NMDA) receptor] and pERK (phosphorylated extracellular signal-regulated kinase) are increased during both incision-induced hyperalgesia and remifentanil-induced hyperalgesia, and again the increases in pNR and pERK were remarkably attenuated by Ru360. Together, our data demonstrate that MCU plays a critical role in remifentanil-induced postoperative mechanical allodynia, with NMDA receptor and ERK as possible downstream effectors. Our findings provide novel mechanisms for remifentanil-induced mechanical allodynia and encourage future studies to examine the mitochondrial Ca2+ uniporter as a potential therapeutic target for prevention of OIH.

Inhibition of NLRP3 Inflammasome Ameliorates Cerebral Ischemia-Reperfusion Injury in Diabetic Mice.

Sustained activation of NLRP3 inflammasome is closely related to diabetes and stroke. However, it is unknown whether NLRP3 inflammasome plays an essential role in stroke in diabetes. We aim to investigate the effect and the potential mechanism of NLRP3 inflammasome in diabetic mice with cerebral ischemia-reperfusion injury. A type 2 diabetic mouse model was induced by a high-fat diet and streptozotocin (STZ). Diabetic mice received MCC950 (the specific molecule NLRP3 inhibitor) or vehicle 60 minutes before the middle cerebral artery occlusion (MCAO) and reperfusion. MCC950 reduced the neurological deficit score of 24 h after cerebral ischemia reperfusion and improved the 28-day survival rate of cerebral ischemia-reperfusion injury in diabetic mice. Furthermore, we found that the mRNA transcription levels of NLRP3, IL-1ß, and caspase-1 in the core ischemic area were remarkably amplified in diabetic mice with cerebral ischemia-reperfusion injury, whereas this phenomenon was obviously attenuated by MCC950 pretreatment. In conclusion, the NLRP3 inflammasome was involved in the complex diseases of diabetic stroke. MCC950, the NLRP3 specific inhibitor, ameliorated diabetic mice with cerebral ischemia-reperfusion injury and improved the 28-day survival rate during the recovery stage of ischemic stroke.

Waste anesthetic gas exposure and strategies for solution.

As inhaled anesthetics are widely used, medical staff have inevitably suffered from exposure to anesthetic waste gases (WAGs). Whether chronic exposure to WAGs has an impact on the health of medical staff has long been a common concern, but conclusions are not consistent. Many measures and equipment have been proposed to reduce the concentration of WAGs as far as possible. This review aims to dissect the current exposure to WAGs and its influence on medical staff in the workplace and the environment, and summarize strategies to reduce WAGs.

High Glucose Enhances Isoflurane-Induced Neurotoxicity by Regulating TRPC-Dependent Calcium Influx.

Isoflurane is a commonly used inhalational anesthetic that can induce neurotoxicity via elevating cytosolic calcium (Ca2+). High glucose regulates the expression of a family of non-selective cation channels termed transient receptor potential canonical (TRPC) channels that may contribute to Ca2+ influx. In the present study, we investigated whether high glucose enhances isoflurane-induced neurotoxicity by regulating TRPC-dependent Ca2+ influx. First, we evaluated toxic damage in mice primary cultured hippocampal neurons and human neuroblastoma cells (SH-SY5Y cells) after hyperglycemia and isoflurane exposure. Next, we investigated cytosolic Ca2+ concentrations, TRPC mRNA expression levels and tested the effect of the TRPC channel blocker SKF96365 on cytosolic Ca2+ levels in cells treated with high glucose or/and isoflurane. Finally, we employed knocked down TRPC6 to demonstrate the role of TRPC in high glucose-mediated enhancement of isoflurane-induced neurotoxicity. The results showed that high glucose could enhance isoflurane-induecd toxic damage in primary hippocampal neurons and SH-SY5Y cells. High glucose enhanced the isoflurane-induced increase of cytosolic Ca2+ in SH-SY5Y cells. High glucose elevated TRPC mRNA expression, especially that of TRPC6. SKF96365 and knock down of TRPC6 were able to inhibit the high glucose-induced increase of cytosolic Ca2+ and decrease isoflurane-induced neurotoxicity in SH-SY5Y cells cultured with high glucose. Our findings indicate that high glucose could elevate TRPC expression, thus increasing Ca2+ influx and enhancing isoflurane-induced neurotoxicity.

Diphenyleneiodonium Mitigates Bupivacaine-Induced Sciatic Nerve Damage in a Diabetic Neuropathy Rat Model by Attenuating Oxidative Stress.

BACKGROUND: Increased oxidative stress has been linked to local anesthetic-induced nerve injury in a diabetic neuropathy (DN) rat model. The current study explores the effects of diphenyleneiodonium (DPI) chloride, an NADPH oxidase (NOX) inhibitor, on bupivacaine-induced sciatic nerve injury in DN rats. METHODS: A rat DN model was established through high-fat diet feeding and streptozotocin injection. The model was confirmed via testing (i) blood glucose, (ii) hindpaw allodynia responses to von Frey (VF) monofilaments, (iii) paw withdrawal thermal latency (PWTL), and (iv) nerve conduction velocity (NCV). Bupivacaine (Bup, 0.2 mL, 5 mg/mL) was used to block the right sciatic nerve. DPI (1 mg/kg) was injected subcutaneously 24 hours and 30 minutes before the sciatic block. At 24 hours after the block, NCV, various reactive oxygen species, and Caspase-3 were evaluated to determine the extent of sciatic nerve injury. RESULTS: The DN rat model was successfully established. Compared with the DN control group, the postblock values of VF responses (DN-Con, 16.5 ± 1.3 g; DN + Bup, 19.1 ± 1.5 g, P < .001) and PWTL significantly increased (DN-Con, 13.3 ± 1.1 seconds; DN + Bup, 14.6 ± 1.1 seconds, P = .028); the NCV of sciatic nerve was significantly reduced (DN-Con, 38.8 ± 2.4 m/s, DN + Bup, 30.5 ± 2.0 m/s, P = .003), and sciatic nerve injury (as indicated by axonal area) was more severe in the bupivacaine-treated DN group (DN-Con, 11.6 ± 0.3 µm, DN + Bup, 7.5 ± 0.3 µm, P < .001). In addition, DPI treatment significantly improved nerve function (VF responses, 17.3 ± 1.3 g; PWTL, 13.4 ± 1.1 seconds; NCV, 35.6 ± 3.1 m/s) and mitigated loss of axonal area (9.6 ± 0.3 µm). Compared to the DN + Bup group (without DPI), the levels of lipid peroxides and hydroperoxides, as well as the protein expression of NOX2, NOX4, and Caspase-3, were significantly reduced in the DN + Bup + DPI group (P < .05). CONCLUSIONS: Subcutaneous injection of DPI appears to protect against the functional and neurohistological damage of bupivacaine-blocked sciatic nerves in a high-fat diet/streptozotocin-induced DN model.

Adipose-derived mesenchymal stem cells therapy for acute kidney injury induced by ischemia-reperfusion in a rat model.

Acute kidney injury (AKI) represents a group of complicated syndromes with a high mortality rate. The administration of adipose-derived mesenchymal stem cells (ADMSCs) has been tested as a possible treatment method for AKI. The long-term evaluation of AKI induced by ischemia/reperfusion (IR) and the probable renal protection of ADMSCs are limited. In this study we have established a rat AKI model induced by IR and investigated the possible protective effects of ADMSCs. Adult Sprague-Dawley (SD) rats were divided into three groups (n = 6/each group). The MOCK group was as the normal control. Rats in the IR-AKI and IR-AKI+ADMSCs groups were subjected to IR injury by clamping both renal pedicles for 40 minutes. Rats in the MOCK and IR-AKI groups were injected with PBS via the tail vein as negative treatment controls. Rats in the IR-AKI+ADMSCs group received ADMSCs therapy (2 × 106 cells were injected into the rats via the tail vein). We found that ADMSC transplantation restored the pathologic morphology induced by IR-AKI to normal compared with the MOCK group, suggesting the reparative function of ADMSCs in kidney tissues. Compared with IR-induced AKI alone, ADMSC treatment significantly decreased the number of apoptotic cells, the level of total urinary protein and serum creatinine, the expression of pro-inflammatory cytokines (IL-6, TNF-α, IL-1ß, IFN-γ, TNF-α, IFN-γ, and TGF-ß), and the inflammation-associated proteins (HGF and SDF1), but increased the expression of the anti-inflammatory cytokine, IL-10, and the anti-apoptotic regulator, Bcl-2. Our data have indicated that ADMSC transplantation may protect against IR-induced AKI by anti-apoptotic and anti-inflammatory effects.

iTRAQ proteomics analysis reveals that PI3K is highly associated with bupivacaine-induced neurotoxicity pathways.

Bupivacaine, a commonly used local anesthetic, has potential neurotoxicity through diverse signaling pathways. However, the key mechanism of bupivacaine-induced neurotoxicity remains unclear. Cultured human SH-SY5Y neuroblastoma cells were treated (bupivacaine) or untreated (control) with bupivacaine for 24 h. Compared to the control group, bupivacaine significantly increased cyto-inhibition, cellular reactive oxygen species, DNA damage, mitochondrial injury, apoptosis (increased TUNEL-positive cells, cleaved caspase 3, and Bcl-2/Bax), and activated autophagy (enhanced LC3II/LC3I ratio). To explore changes in protein expression and intercommunication among the pathways involved in bupivacaine-induced neurotoxicity, an 8-plex iTRAQ proteomic technique and bioinformatics analysis were performed. Compared to the control group, 241 differentially expressed proteins were identified, of which, 145 were up-regulated and 96 were down-regulated. Bioinformatics analysis of the cross-talk between the significant proteins with altered expression in bupivacaine-induced neurotoxicity indicated that phosphatidyl-3-kinase (PI3K) was the most frequently targeted protein in each of the interactions. We further confirmed these results by determining the downstream targets of the identified signaling pathways (PI3K, Akt, FoxO1, Erk, and JNK). In conclusion, our study demonstrated that PI3K may play a central role in contacting and regulating the signaling pathways that contribute to bupivacaine-induced neurotoxicity.

Curcumin Attenuated Bupivacaine-Induced Neurotoxicity in SH-SY5Y Cells Via Activation of the Akt Signaling Pathway.

Bupivacaine is widely used for regional anesthesia, spinal anesthesia, and pain management. However, bupivacaine could cause neuronal injury. Curcumin, a low molecular weight polyphenol, has a variety of bioactivities and may exert neuroprotective effects against damage induced by some stimuli. In the present study, we tested whether curcumin could attenuate bupivacaine-induced neurotoxicity in SH-SY5Y cells. Cell injury was evaluated by examining cell viability, mitochondrial damage and apoptosis. We also investigated the levels of activation of the Akt signaling pathway and the effect of Akt inhibition by triciribine on cell injury following bupivacaine and curcumin treatment. Our findings showed that the bupivacaine treatment could induce neurotoxicity. Pretreatment of the SH-SY5Y cells with curcumin significantly attenuated bupivacaine-induced neurotoxicity. Interestingly, the curcumin treatment increased the levels of Akt phosphorylation. More significantly, the pharmacological inhibition of Akt abolished the cytoprotective effect of curcumin against bupivacaine-induced cell injury. Our data suggest that pretreating SH-SY5Y cells with curcumin provides a protective effect on bupivacaine-induced neuronal injury via activation of the Akt signaling pathway.

Moderate hypothermia ameliorates enterocyte mitochondrial dysfunction in severe shock and reperfusion.

BACKGROUND: Hypothermia can ameliorate ischemia-reperfusion-induced intestinal injury; however, whether the therapeutic mechanism of hypothermia on hemorrhagic shock, a severe condition of ischemia-reperfusion, is associated with mitochondrial protection in enterocytes is rarely reported. We aimed to evaluate the effects of hypothermia on mitochondria after shock-induced intestinal injury. MATERIALS AND METHODS: A severe hemorrhagic shock model was constructed in Sprague-Dawley rats at induced hypothermic (32°C or 34°C) or normothermic temperatures (37°C), followed by resuscitation with whole shed blood and Ringer lactate (15 mg/kg body weight). After 2 h, 24 rats were killed and their intestinal tissue was collected; the remaining animals were returned to the normothermic environment to observe the survival time. RESULTS: There was severe mitochondrial dysfunction in the normothermia group, as well as increased oxidative stress and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling apoptotic index. As expected, hypothermia treatment decreased mitochondrial permeability transition pore opening and restored the mitochondrial membrane potential and intracellular adenosine triphosphate content. Furthermore, hypothermia elevated mitochondrial-reduced glutathione and decreased mitochondrial malondialdehyde; consistent with the restored mitochondrial function, intestinal cell apoptosis and intestinal histopathologic injury were attenuated, the systemic inflammatory response was mitigated, and survival time was significantly prolonged. Additionally, moderate-induced hypothermia (32°C) had better therapeutic effects than mild hypothermia (34°C). CONCLUSIONS: The results suggest that moderate hypothermia resuscitation is an effective treatment for shock-induced intestinal injury, and its therapeutic mechanism may be related to mitochondrial protection.

Emulsified Isoflurane Protects Against Transient Focal Cerebral Ischemia Injury in Rats via the PI3K/Akt Signaling Pathway.

BACKGROUND: Phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) pathway activation may promote neuronal survival via neuroprotection during inflammation after cerebral ischemia. In this study, we investigated whether IV pretreatment with emulsified isoflurane (EI) could decrease ischemic brain injury related to the PI3K/Akt pathway. METHODS: Male Sprague-Dawley rats received different doses of IV EI (1, 2, 4, or 8 mL/kg/h) or Intralipid (8 mL/kg/h) for 30 minutes (n = 6-12 per group), followed by middle cerebral artery occlusion (MCAO) for 100 minutes to induce transient focal ischemia. The neurologic score and infarct volume were measured 48 hours after MCAO. Immunostaining, Western blot analysis, and an enzyme-linked immunosorbent assay were used to assess EI effects on the cell inflammatory response, high-mobility group box-1 release, and phosphorylated Akt (expression. LY294002, a PI3K inhibitor, was also infused into the ventricular space before EI to determine the effect of EI. RESULTS: Four milliliters per kilogram per hour of EI reduced the infarct size (21.08 ± 11.24 vs 37.09 ± 10.46, P = 0.006), improved neurologic scores after MCAO (1.13 ± 0.48 vs 1.95 ± 0.65, P = 0.015), significantly reinforced neuronal survival (982.7 ± 364.4 vs 439.8 ± 278.4, P = 0.036), and inhibited CD68 macrophage/macroglial infiltration in the ischemic core (188.2 ± 49.1 vs 282 ± 49.4, P = 0.018) compared with the vehicle group. In the EI pretreatment group, the serum high-mobility group box-1 concentration (3.62 ± 0.72 vs 5.73 ± 0.65, P < 0.001) was decreased, and the cerebral phosphorylated Akt level (50.33 ± 4.73 vs 37.5 ± 3.11, P = 0.007) was increased at 48 hours, which was inhibited by LY294002 compared with the vehicle group (5.31 ± 0.72 vs 5.73 ± 0.65, P = 0.216; 43.00 ± 4.84 vs 37.5 ± 3.11, P = 0.091). CONCLUSIONS: These findings suggest that EI pretreatment protects against ischemic brain injury via the inhibition of cerebral inflammation and is associated with the PI3K-Akt pathway in rats with MCAO. This drug may be a novel therapeutic agent for patients after stroke.